Structural component, especially shielding part

ABSTRACT

Structural component, especially a shielding part.  
     The invention relates to a structural component, especially a shielding part, with structural parts which are configured at least in part differently in terms of their superficial extension and/or the direction in which the extend, of which parts there is at least one structural part of a first type ( 10 ). In that the structural parts of a second type ( 34 ) are formed from the structural part of the first type ( 16 ) such that hollow section-like receiving channels ( 36 ) which are curved in at least two directions are molded into the structural part of the first type ( 10 ) and that the respective receiving channels ( 36 ) in one direction of curvature follow the curvature of the structural part of the first type ( 10 ), thermal components, such as for example the curved exhaust lines of the exhaust system, can be accommodated in an integrating manner, and effective thermal shielding and noise insulation is ensured by overlapping.

The invention relates to a structural component, especially a shielding part, with structural parts which are configured at least in part differently in terms of their superficial extension and/or the direction in which they extend, of which parts at least one structural part of a first type is provided with a curvature.

While heat development for example of an economical power-optimized diesel engine on the engine block can be very low, this in no way applies to “hot zones” as in the manifolds, turbochargers, catalytic converters, etc. Due to the increasingly compact configuration of engines, components which are not thermally “compatible” are increasingly ending up in close proximity. Accordingly, it is necessary, using so-called shielding parts, such as heat shields, to protect thermal engine components facing adjacent heat-sensitive assemblies, such as sensors, fuel lines, pressurized sensors, body parts, etc. The situation is also exacerbated by the compact structure in that the high packing density of the assemblies constricts the cooling air flow in the engine compartment. Noise abatement measures may also contribute to this. Thus, for example, plastic bottom plates which are designed to reduce the emergence of noise from the engine compartment onto the roadway under certain circumstances can produce effective insulation with which heat is contained in the engine compartment. Catalytic converters, due to their phased high surface temperature, are considered heat sources which certainly necessitate the use of protective shield barriers. One typical example of this are design-engineering measures such as positioning of the catalytic converter tightly on the manifold of the overall exhaust system. This design principle, which is used for rapid heat-up of the catalytic converter and thus for reducing emissions in the cold starting phase, shifts a strong heat source into the engine compartment where numerous assemblies are crowded in a narrow space. Likewise, one cause of the growing importance of shielding parts such as heat shields is the tendency towards use of thermoplastics. The outstandingly moldable, light and economical materials are becoming noticeably more common in the engine compartment, but require special attention with respect to the ambient temperatures at the application site, relative to the other thermal engine parts (New Materials and Development Tools for Heat Protection, in MTZ 12/2001, Volume 62, page 1044 ff.).

DE 102 47 641 B3 discloses a structural component, especially in the form of a noise-damping shielding part as a component of the motor vehicle. In order to improve noise abatement in the known structural component, the pertinent shielding part consists of a shielding body with a base edge as a structural part of the first type which may be mounted on the edge side by way of angular clamp legs within the engine compartment on the stationary parts there, and shields thermal engine components facing heat-sensitive components.

The shielding body as a structural part of the first type is arched in a U-shape in the middle area and in addition is configured to be symmetrical in this respect. The middle area which is arched in a U-shape on the edge side into the edge areas undergoes transition into greater curvature, on the two opposing edge areas the angular clamps being mounted subsequently as fastening means. The shielding body consists of two layers of sheet metal, between which a noise-damping and/or heat insulating insulation layer extends, and to fasten the cover layers of sheet metal to one another, flanging is used in which the free flared flange of one cover layer superficially encloses the edge area of the other cover layer. To reduce weight, the shielding body is made of aluminum or some other lightweight metal.

The known solution is used preferably for shielding a coupling between the transmission flange and a universal shaft against structure-borne noise which originates from the transmission as well as the continuous influence of the temperature radiation of the adjacently running exhaust pipe. During tests, a reduction of noise emission by 3 dB was achieved in the known solution. In order to achieve the pertinent shielding action, other structural parts of a second type which extend in the form of bead-shaped lengthwise and transverse ribs over the convex outer side of the shielding body extend along the middle area of the first structural part in the form of a shielding body. It is characteristic in this known structuring that the lengthwise ribs which extend over the entire length of the shielding body are adjoined by transverse ribs which are molded on in one piece, which transverse ribs form a type of nub structure, and which fit adjacently between two respective transverse ribs of an adjacent lengthwise rib in an alternating sequence at intermediate distances. The edge areas which are curved more dramatically to the outside with the connecting clamps are conversely kept free of the aforementioned ribs. With respect to the interrupted transverse rib structure of the known solution, it is to be expected that stiffness and strength are reduced in this respect. Furthermore, at the transition site to the connecting clamps, stiffening of the shielding body is acquired only by way of the bent clamp legs which in this regard largely define the connection geometry, here of the structural component on the stationary engine components or chassis components; this limits the possible applications of the known structural part accordingly. The connecting clamps with their bent clamp legs and eye connecting points for penetration of a fastener (screw) on the one hand require installation space and on the other they increase the weight for the known solution. Nor is the known solution suited for thermal insulation of larger areas in the engine compartment.

On the basis of this state of the art, the object of the invention is to further improve a structural component of the type indicated while retaining its advantages, specifically ensuring very good sound and heat insulation, such that less installation space is required, that it can be used in a more versatile manner, with simultaneously increased stiffness and strength and reduced weight with production costs which can be comparably fixed, and is also especially suited for thermal insulation of larger areas within an engine compartment. This object is attained by a structural component with the features specified in claim 1 in its entirety.

In that, as specified in the characterizing part of claim 1, the structural parts of the second type are formed from a structural part of the first type such that hollow section-like receiving channels which are curved in at least two direction are molded into the structural part of the first type and that the respective receiving channels in one direction of curvature follow the curvature of the structural part of the first type, thermal components, such as for example the curved exhaust lines of an exhaust system, can be accommodated in an integrating manner so that this accommodation saves installation space and by overlapping with the respective receiving channel there is effective thermal shielding and shielding of the noise emissions which occur in the form of structure-borne noise or airborne noise. Although the structural component as claimed in the invention is very large in two dimensions, due to the special configuration on the structural parts of the first and second type it is stiffened such that excess natural vibrations, which typically have an adverse effect on service life, are also largely precluded.

The receiving channels which are convex viewed from their outer or top side are configured as bead-shaped stiffening ribs with an enlarged cross section and they follow the curvature of the first structural part with its two-dimensional extension. In the area of the change in curvature, toward the edge area stiffening of the entire edge structure of the shielding body thus produced takes place; the shielding body which can be configured in the manner of a flat trough also helps save installation space in conjunction with the integrating accommodation of parts of the exhaust gas system and moreover requires little weight.

Fastening of the structural component to the other engine components can be achieved cost-effectively by way of known fastening clamps and furthermore screw connections with damper elements can also be used. By means of different structural parts the overall structural component can also be stiffened such that a type of shielding armor is implemented with a natural vibration behavior which can be referred to as noncritical so that the structural component solution as claimed in the invention can be used expediently in particular where major occurrence of vibrations can be expected in operation. In addition to these advantages, the basic structure which has been stiffened in this way results in a clear reduction of sound propagation of noisy engine components.

In order to keep the thermal burden on the structural component low, provision is preferably made such that the individual receiving channels spaced apart from one another extend on the top of the structural component of the first type which overlaps the respective exhaust section of the engine while maintaining a definable distance. The force which prevails between the inside of the respective receiving channel and the outside of the exhaust gas lines of the exhaust section also reduces the propagation of unwanted noise emissions.

In another especially preferred embodiment of the structural component as claimed in the invention, provision is made such that the structural part of the first type undergoes transition into a sleeve-like structural part of the third type which is kept essentially free of stiffening elements in the direction of the structural part of the first type over a definable surface area and that this surface area is adjoined by another surface area with stiffening elements as a structural part of the fourth type. As a result of this sleeve-like configuration of the structural part of the third type, other heat-critical engine components such as the catalytic converter can be shielded accordingly relative to the environment and with the overall structural component with its individual structural parts which are joined preferably in one piece to one another, a very large area on the engine is thermally insulated without the occurrence of excess natural vibrations having an adverse effect on service life. By interrupting the structural parts which are connected in one piece to one another by way of a structural part which is kept free of stiffening elements over a definable surface area, sudden stiffness changes occur in the respective shoulders and the offset planes of the structural component, with the result that any vibration which may occur cannot propagate undisturbed through the component. This results in an additional damping effect of the vibrations which occur; this keeps noise emissions low.

Other advantageous embodiments of the structural component as claimed in the invention are the subject matter of the other dependent claims.

The structural component as claimed in the invention will be described in greater detail below with the aid of one embodiment illustrated in the drawings in which in schematic form and not drawn to scale

FIG. 1 shows in a perspective a side view of the structural component in the installed state;

FIG. 2 shows a bottom view of the structural component in the installed state with the exhaust section and catalytic converter positioned in front.

FIGS. 1 and 2 show the structural component as claimed in the invention as a whole, configured especially in the form of a shielding part, and designed to thermally insulate larger areas within the engine compartment and to reduce noise emissions in the form of structure-borne and airborne noise. The structural component has structural parts which are configured differently in terms of their superficial extension and/or the direction in which they extend, of which at least one structural part of a first type 10 is provided with a curvature which follows the curved path of the exhaust section 12 with its individual exhaust lines 14 (total of four pieces). The pertinent exhaust lines 14 with their top discharge into a common connecting flange piece 16 with which the exhaust section 12 can be connected to a conventional four-cylinder internal combustion engine of a motor vehicle. On its other opposite end, the finger-like exhaust lines 14 discharge into a common connecting piece 20 which has the shape of the palm of the hand and which in turn undergoes transition by way of a conically widening enlargement piece 20 into a catalytic converter 22 with a cylindrical outside peripheral wall which, consisting of sheet metal parts, is provided with lengthwise ribs 24 and transverse ribs 26. Viewed in the direction of looking at FIG. 1, the catalytic converter 22 on its bottom is provided with a connecting flange 28 to which a conventional vehicle-specific exhaust system can be connected. Supported by way of retaining devices 30, a tubular connecting body 32 for holding a conventional oil dipstick (not detailed) furthermore extends along the structural component. On the top of the structural part of the first type 10, there are four structural parts 34 of a second type, the pertinent structural parts of the second type 34 being formed from the structural part of the first type 10 by receiving channels 36 which are concave in cross section, viewed from the inside, (cf. FIG. 2) being molded into the structural part of the first type 10.

The structural parts of the first and second type 10, 34 viewed in the direction of looking at the figures on their top discharge into an angular connecting piece 38 which is used to fasten the entire structural component in the area of its top end on the engine components or other vehicle components which are not detailed. For stiffening in this area, there are projection-like or nub-like stiffening elements 40 which especially at the transition of the connecting piece 38 to the structural parts of the second type 34 border them essentially on the edge side and thus stiffen them. Furthermore, at least one outside structural part of the second type 34 has transversely extending stiffening ribs 42 in the edge area of the structural part of the first type 10 in which the amounts of material which are not needed for the actual structures are placed when the structural component as a whole is being molded, so that otherwise the molding extends essentially smoothly. The structural parts of the second type 34 in the manner of fingers or a glove extend over the individual exhaust lines 14 and the receiving channels 36 thus configured maintain a definable distance to the top of the exhaust lines 14. But the individual exhaust lines 14 with their curved top are routed along the inside of the receiving channels 36 and as a result are at least partially encapsulated in the manner of shielding. In particular, the two outer structural parts of the second type 34 are lengthened with their free edge-side borders and in this way in a shell-like manner encompass the two outer edge zones of the exhaust section 12 with their exhaust lines 14 (cf. FIG. 2).

As shown in particular in FIG. 1, the flat structural part of the first type 10 undergoes transition into a sleeve-like structural part of the third type 44, which in the direction of the structural part of the first type 10 is kept essentially free of stiffening elements over a definable surface area, this surface area which has been kept free being adjoined by another surface area with stiffening elements 44 as structural parts of the fourth type. The stiffening elements 46 are configured in the manner of the projecting transverse ribs and are molded into the structural part of the third type 44, their extending with definable distances to one another essentially transversely to the receiving channels 36 and otherwise parallel to the transverse ribs 26 of the enveloping jacket for the catalytic converter 22.

Accordingly, the structural component as claimed in the invention can be divided such that the structural component of the first type 10 with the receiving channels 36 follows the curvature area of the exhaust lines 14 of the exhaust section 12 and the structural component of the third type as another shell-shaped (sleeve-like) component partially overlaps the enlargement piece 20 and the catalytic converter 22. Furthermore, the structural components of the second and fourth type 34 and 46 are located in the end-side termination areas of the structural component and the middle area which lies in between is kept free of stiffening elements. Furthermore, the respective stiffening elements 46 extend between two shaped surfaces 48 as structural parts of a fifth type which project in the direction of the top of the structural component in the same manner as the individual stiffening elements 46. In addition to additional edge-side stiffening, the shaped surfaces 48 allow insertion of fasteners 50 for fastening the structural component on definable engine components, here in the form of a catalytic converter 22. Furthermore, for good stiffening it has proven favorable to provide at least the respective structural part of the third type 44 with a taper as shown at least on the respectively edge-side transition point 52 from the structural part of the first and second type 10, 34. Furthermore, in a trough-shaped depression between two adjacent structural parts of the second type 34 at the site of the transition to the structural part of the third type 44, there is a recess 54 which is designed for insertion of a lambda probe.

As a result of the special structure of the overall component, in the respective shoulders and in the offset planes “sudden changes of stiffness” occur so that any vibrations which may arise cannot propagate undisturbed through the component. As a result, additional damping of vibrations occurs and furthermore a distinctly increased service life of the overall system is achieved. The structural component preferably is made of a conventional steel or sheet metal material and may also consist of high-grade steel material. The structural component may be made with one or more layers, and for a multilayer structure there is preferably an insulating intermediate layer of the conventional type between two cover layers (not shown). 

1. A structural component, especially a shielding part, with structural parts which are configured at least in part differently in terms of their superficial extension and/or the direction in which they extend, of which parts at least one structural part of a first type (10) is provided with a curvature, and with structural parts of a second type (34), characterized in that the structural parts of the second type (34) are formed from a structural part of the first type (16) such that hollow section-like receiving channels (36) which are curved in at least two directions are molded into the structural part of the first type (10) and that the respective receiving channels (36) in one direction of curvature follow the curvature of the structural part of the first type (10).
 2. The structural component as claimed in claim 1, wherein the individual receiving channels (36) spaced apart from one another extend on the top of the structural part of the first type (10) which at least partially overlaps the exhaust section (12) of the engine while maintaining a definable distance, and wherein the curved exhaust lines (34) extend at least in part in the respectively assignable receiving channels (36).
 3. The structural component as claimed in claim 1, wherein the structural part of the first type (10) is bordered on the edge side by one respective structural part of the second type (34).
 4. The structural component as claimed in one of claims 1 wherein the structural part of the first type (10) undergoes transition into a sleeve-like structural part of the third type (44) which is kept essentially free of stiffening elements in the direction of the structural part of the first type (10) over a definable surface area, and wherein this surface area is adjoined by another surface area with stiffening elements (46) as the structural part of the fourth type.
 5. The structural component as claimed in claim 4, wherein the stiffening elements (46) are configured in the manner of transverse ribs which extend with definable distances to one another essentially transversely to the receiving channels (36).
 6. The structural component as claimed in claim 4, wherein the sleeve-like structural part of the third type (44) overlaps a catalytic converter (22), preferably while maintaining a distance, which adjoins the exhaust section (12).
 7. The structural component as claimed in claim 4, wherein the respective stiffening elements (46) as a structural part of the fourth type extend between two shaped surfaces (48) as a structural part of a fifth type which project in the direction of the top of the structural component, in the same manner as the individual stiffening elements (46).
 8. The structural component as claimed in claim 7, wherein the respective shaped surface (48) is penetrated by at least one fastener (50) for fastening the structural component on definable components, such as engine components and/or other vehicle components.
 9. The structural component as claimed in ene of claims 4, wherein at least the structural part of the third type (44) is provided with a taper at least on the respective edge-side transition point (52) from the structural part of the first and second type (10, 34).
 10. The structural component as claimed in claim 1, wherein there is a depression (54) between two adjacent structural parts of the second type (34) at the site of the transition to the structural part of the third type (44) for insertion of a lambda probe. 